This invention relates to electronic musical instruments, and, more particularly, to an electronic musical instrument of a key code processing type in which a signal concerning the highest note (or the lowest note) is selected out of key operating signals supplied in time division manner, thereby to produce the musical tone of the highest note (or the lowest note) thus selected.
Some high grade electronic musical instruments have a solo keyboard in addition to ordinary upper, lower and pedal keyboards. Of course, with such a high grade electronic musical instrument, a plurality of keys can be operated simultaneously in the upper keyboard or the lower keyboard. Usually a solo performance can be effected by operating a single key in the solo keyboard while operating a plurality of keys in the upper or lower keyboard. However, since the provision of the solo keyboard is required for such a solo performance, the keyboard assembly of the electronic musical instrument is necessarily bulky, which results in an increase of the manufacturing cost. Thus, in general, such a solo keyboard is employed only for the highest grade electronic musical instrument.
Accordingly, an object of this invention is to provide an electronic musical instrument in which the same performance effect as a solo performance on a separate keyboard can be obtained without a solo keyboard.
In the electronic musical instrument according to the invention, a single key (corresponding to the highest note or the lowest note) is selected out of a plurality of keys depressed in a keyboard and the musical tone of the single key thus selected is produced, whereby the same performance effect as a solo performance effect is automatically obtained. In this case, the musical tones of the plurality of keys depressed are, of course, produced together with the musical tone of the selected single key.
It is well known in the art to employ a priority connection circuit, in which key switches are connected in a priority connection manner, in order to select a single key out of a plurality of keys. However, the employment of such a priority circuit is not preferable because the use of the priority circuit makes the keyboard circuit intricate and makes the arrangement of circuits relating to the keyboard bulky. Means for effectively simplifying the keyboard circuit and the circuitry concerning the keyboard circuit is to process key data in time division manner. An electronic musical instrument employing this time division process technique is known in the art.
This invention is intended to achieve the aforementioned object with the electronic musical instrument employing the time division process system. According to the invention, a single data selecting circuit is provided, which can select the key data of the highest note or the lowest note out of key data supplied in time division manner, so that a musical tone is produced according to the single key data thus selected.